Organic Brain Biopsychology Chapter 5
Terms
undefined, object
copy deck
- 6-Hydroxydopamine (6-OHDA)
- a chemical that is absorbed by neurons that release dopamine or norepinephrine; it then oxidized into toxic chemicals that kill those neurons.
- Ablation
- the removal of a structure.
- Action potential
- rapid depolarization and slight reversal of the usual polarization caused by stimulation beyond the threshold.
- Amphetamine
- stimulant drug that increases the release of dopamine.
- Apomorphine
- morphine derivative that stimulates dopamine receptors.
- Apoptosis
- developmental program by which a neuron kills itself at a certain age unless inhibited from doing so.
- Axons
- single thin fibers of constant diameter that extend from a neuron.
- Blood-brain barrier
- the mechanism that keeps many chemicals out of the brain.
- Central nervous system (CNS)
- the brain and spinal cord.
- Cerebrospinal fluid (CSF)
- liquid similar to blood serum, found in the ventricles of the brain and in the central canal of the spinal cord.
- Closed head injury
- sharp blow to the head resulting from a fall, an automobile or motorcycle accident, an assault, or other sudden trauma that does not actually puncture the brain.
- Cocaine
- stimulant drug that increases the stimulation of dopamine synapses by blocking the reuptake of dopamine by the presynaptic neuron.
- Collateral sprout
- newly formed branch from an uninjured axon that attaches to a synapse vacated when another axon was destroyed.
- Deafferent
- to remove the sensory nerves from a body part.
- Dendrite
- branching fiber that emanates from a neuron, growing narrower as it extends from the cell body toward the periphery.
- Denervation supersensitivity
- increased sensitivity by a postsynaptic cell after removal of an axon that formerly innervated it.
- Diaschisis
- decreased activity of surviving neurons after other neurons are damaged.
- Differentiation
- formation of the axon and dendrites that gives a neuron its distinctive shape.
- Disuse supersensitivity
- increased sensitivity by a postsynaptic cell because of decreased input by incoming axons.
- Dopamine
- a neurotransmitter.
- Edema
- accumulation of fluid.
- Evolution
- change in the frequencies of various genes in a population over generations.
- Fetal alcohol syndrome
- condition resulting from prenatal exposure to alcohol and marked by decreased alertness, hyperactivity, varying degrees of mental retardation, motor problems, heart defects, and facial abnormalities.
- Focal hand dystonia
- musician's cramp, a condition in which the touch responses to one finger overlap those of another, leading to clumsiness, fatigue, and involuntary movements.
- GABA (gamma amino butyric acid)
- the most abundant inhibitory neurotransmitter.
- Ganglioside
- molecule composed of carbohydrates and fats.
- Glutamate
- the most abundant excitatory neurotransmitter.
- Hemorrhage
- the rupture of an artery.
- Hormones
- chemicals secreted by glands and conveyed by the blood to other organs, which are influenced by their activity.
- Ischemia
- local insufficiency of blood because a blood clot or other obstruction has closed an artery.
- Kennard principle
- generalization (not always correct) that it is easier to recover from brain damage early in life than later.
- Lesion
- damage to a structure.
- Magnetic resonance imaging (MRI)
- method of imaging a living brain by using a magnetic field and a radio frequency field to make atoms with odd atomic weights all rotate in the same direction and then removing those fields and measuring the energy that the atoms release.
- Magnetoencephalograph (MEG)
- a device that measures the faint magnetic fields generated by the brain's activity.
- Migration
- the movement of neurons toward their eventual destinations in the brain.
- Myelin sheath
- insulating material that covers many vertebrate axons.
- Myelination
- development of a myelin sheath that insulates an axon.
- Nerve growth factor (NGF)
- protein that promotes the survival and growth of axons in the sympathetic nervous system and certain axons in the brain.
- Neural Darwinism
- the principle that, in the development of the nervous system, synapses form haphazardly at first, and then a selection process keeps some and rejects others.
- Neurons
- cells that receive information and transmit it to other cells by conducting electrochemical impulses. See also Synapses.
- Neurotrophin
- a chemical that promotes the survival and activity of neurons.
- Penumbra
- area of endangered cells surrounding an area of primary damage.
- Phantom limb
- the continuing sensation of an amputated body part.
- Postcentral gyrus
- a gyrus of the cerebral cortex just posterior to the central gyrus; a primary projection site for touch and other body sensations.
- Postsynaptic neuron
- a neuron on the receiving end of a synapse.
- Prefrontal cortex
- the anterior portion of the frontal lobe of the cortex, which responds mostly to the sensory stimuli that signal the need for a movement.
- Primates
- monkeys, apes, and humans.
- Progesterone
- a steroid hormone which, among other functions, prepares the uterus for the implantation of a fertilized ovum and promotes the maintenance of pregnancy.
- Proliferation
- the production of new cells.
- Sham lesion
- a control procedure for an experiment, in which an investigator inserts an electrode into a brain but does not pass a current.
- Somatosensory system
- the sensory network that monitors the surface of the body and its movements.
- Spinal cord
- the part of the CNS found within the spinal column; it communicates with the sense organs and muscles below the level of the head.
- Stem cells
- undifferentiated cells that can divide and produce daughter cells that develop more specialized properties.
- Stereotaxic instrument
- a device for the precise placement of electrodes in the head.
- Stimulant drugs
- drugs that tend to produce excitement, alertness, elevated mood, decreased fatigue, and sometimes increased motor activity.
- Stroke (cerebrovascular accident)
- the temporary loss of normal blood flow to a brain area.
- Synapses
- points of communication at the gap between two neurons or between a neuron and a muscle.
- Synaptogenesis
- the formation of synapses.
- Tectum
- the roof of the midbrain.
- Tissue plasminogen activator (tPA)
- a drug that breaks up blood clots.